1. University of Kansas School of Medicine, Kansas City, Kansas.
2. Department of Pediatrics and Adolescent Medicine, Center of Adolescent Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
3. The University Hospitals' Centre for Health Research (UCSF), Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.
4. Institute of Public Health, University of Copenhagen, Copenhagen, Denmark.
5. Department of Pediatrics and Adolescent Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark.